ACTG 219 is a longitudinal study of infants, children, and adolescents who have participated in perinatal and pediatric AIDS Clinical Trial Group clinical treatment trials in order to monitor long term survival and quality of life. ACTG clinical trials evaluate short term efficacy, safety and toxicity, however long term outcomes and benefits of treatments, particularly on growth and development, cannot be adaquately assesses during the time frame of a clinical trial. Children enrolled will be studied from enrollment to age 21.